The present invention relates to absorbent articles which are adapted to contain body exudates. More particularly, the invention pertains to pant-like disposable absorbent articles having non-irritating refastenable seams, and methods of making such disposable absorbent articles.
Current disposable absorbent training pants for children going through the potty training stage have proved to be a particularly desirable and useful product. Such training pants generally include an absorbent chassis including a liquid impervious outer cover, a liquid pervious bodyside liner and an absorbent structure. The training pants further include stretchable side panels that are permanently bonded to opposite side edges of the absorbent chassis. The chassis and side panels thereby form a unitary waist opening and two leg openings. The fit of the pants may be further enhanced by gathering means along the waist and leg openings.
The components of traditional training pants are permanently seamed together to provide a pant product. Thus, traditional training pants do not employ fastening components such as hook-and-loop type fasteners which can irritate the skin if the fastening components come in contact with the wearer. Moreover, traditional training pants are useful in the toilet training process because the pant has a very garment-like look. Children identify diaper products with babies, and most children do not like being identified with or as babies. Consequently, these children do not want to wear baby diapers, and instead prefer to wear training pants that look like adult underwear. Thus, the switch from a traditional diaper to a more garment-like or underwear-like training pant can be an important step in the toilet training process.
One drawback with current training pants, however, is that the manner of applying them is limited to being pulled on like a pant. Applying the product like a pant is advantageous in many instances, and is particularly suited for active, walking children. Even for the same child, however, there may be times when it would be useful to apply the product like a diaper. For instance, it might be more convenient to apply the product like a diaper when there is a desire not to remove the child""s shoes. Because it is difficult to know when a particular mode of applying the garment will be needed, it is beneficial to have a garment that is adaptable to being used either as a diaper or as a pant. This is preferable to keeping both types of garments available. A product that can be applied either like a diaper or a pant permits the interior of the product to be easily checked without having to pull the product downward.
Thus, it would be desirable to have a disposable absorbent article that provides the garment-like look of a traditional training pant, includes fastening components to allow application either like a diaper or a pant, and minimizes the likelihood of fastening components coming into contact with the skin of the wearer.
In response to the above-referenced unfulfilled need in the art, a new pant-like disposable absorbent article with shaped fastening components and a method of making such a disposable absorbent article have been discovered. The absorbent article includes a fastening system that can be repeatedly fastened, unfastened and refastened. The fastening components have interior corners near the leg openings that are recessed to avoid possible irritation of the wearer""s skin.
In one embodiment, the present invention pertains to an absorbent article including an absorbent chassis and a fastening system. The absorbent chassis defines a longitudinal axis, a transverse axis, opposite first and second waist regions, and a crotch region which extends between and interconnects the first and second waist regions. The fastening system includes first and second fastening components disposed in the first waist region and adapted to releasably engage at least one mating fastening component disposed in the second waist region. Each first and second fastening component defines an interior corner disposed toward the longitudinal and transverse center of the absorbent chassis, and the interior corner is recessed.
The fastening components and the mating fastening components form refastenable seams for securing the first and second waist regions together. The refastenable seams allow the product to be either pulled on like a pant or applied like a diaper. If the training pant becomes soiled during use, the fastening components can be disengaged from the mating fastening components to easily remove the training pant from the waist of the wearer with reduced risk of undesirably soiling the clothes or legs of the wearer. Further, the fastening components can also be easily disengaged from the mating fastening components to inspect the training pant for possible soiling. Thus, the training pant is configured to be pulled on or off over the hips of the wearer such as conventional training pants and can be readily applied or removed by disengaging the fastening components similar to conventional diapers. Moreover, the first and second fastening components can be repositioned if necessary after the training pant has been pulled on over the legs and hips of the wearer.
The interior corners are recessed relative to their inner end edges and inner side edges in order to minimize skin irritation. When the fastening system is engaged, a relatively high degree of separation force is concentrated near the leg openings of the absorbent article. This relatively high degree of separation force tends to cause the fastening components to separate from one another in a shear mode and/or peel mode near the inner end edges of the fastening components. By recessing the interior corners as disclosed in greater detail hereinafter, the likelihood of the fastening components coming into contact with the skin of the wearer are significantly reduced.
The degree to which the interior corners are recessed can be defined in terms of a boundary arc. The boundary arc represents a radius taken a fixed distance from two imaginary lines emanating from the inner side edge of the fastening component and from the longitudinally innermost point of the fastening component. For purposes of the present invention, the fixed distance is about 2 centimeters, particularly about 1.5 centimeters, such as exactly 1.5 centimeters, and more particularly about 1 centimeter, such as exactly 1 centimeter, for improved performance.
The refastenable seams are formed when the first and second fastening components are engaged with the mating fastening components. The refastenable seams are desirably relatively thin, narrow and flexible to afford the look and feel of a cloth garment. Thus, in particular embodiments, the refastenable seams have a length-to-width ratio of about 2 or greater, such as about 2 to about 25, particularly about 5 or greater, such as about 5 to about 8. The refastenable seams define a length dimension and a width dimension that is perpendicular to the length dimension. For a child of about 9 to about 15 kilograms (20-34 lbs.), for example, the length dimension is desirably from about 5 to about 13 centimeters, such as about 10 centimeters, and the width dimension is desirably from about 0.5 to about 3 centimeters, such as about 2 centimeters. Desirably although not necessarily, the length dimension is aligned generally parallel to the longitudinal axis of the absorbent article and the width dimension is aligned generally parallel to the transverse axis of the absorbent article. The term xe2x80x9cgenerally parallelxe2x80x9d as used herein refers to an angle within about 35 degrees or less of the referenced axis, and more particularly within about 20 degrees or less of the referenced axis.
The fastening components can comprise any refastenable fasteners suitable for absorbent articles, and desirably comprise mechanical fastening elements rather than adhesive fastening elements. Suitable mechanical fastening elements can be provided by interlocking geometric shaped materials, such as hooks, loops, bulbs, mushrooms, arrowheads, balls on stems, male and female mating components, buckles, snaps, or the like. In particular embodiments, the fastening components and mating fastening components comprise hook-and-loop fastening elements. One skilled in the art will recognize that the shape, density and polymer composition of the hooks and loops can be selected to obtain the desired level of securement between the fastening components and the mating fastening components. A more aggressive hook material can comprise a material with a greater average hook height, a greater percentage of directionally-aligned hooks, or a more aggressive hook shape.
As disclosed in copending U.S. patent application Ser. No. 60/112,709, filed on Dec. 18, 1998 by C. P. Olson et al. and titled xe2x80x9cAbsorbent Articles Having Differential Strength Refastenable Seam,xe2x80x9d the refastenable seam may include one or more main refastenable attachment zones and one or more enhanced refastenable attachment zones. The main and enhanced refastenable attachment zones may be constructed to provide differential levels of securement, and particularly augmented levels of securement at locations which are subject to greater levels of separation forces.
As disclosed in copending U.S. patent application Ser. No. 60/112,775, filed on Dec. 18, 1998 by C. P. Olson and titled xe2x80x9cAbsorbent Articles Having Hinged Fasteners,xe2x80x9d the refastenable seam may comprise individual fastening materials with narrow spacings therebetween. The narrow spacings provide a desirable hinge to improve fit and securement of the fastening components.
The disclosed absorbent articles are adapted to be worn adjacent to the body of a wearer to absorb and contain various exudates discharged from the body. The absorbent articles are desirably pre-fastened to provide a pant-like product for the user. The product can then be pulled on like a conventional training pant, and subsequently checked or removed with the ease of a diaper-like product. Moreover, the product may be applied like a diaper rather than like a pant. Supplemental releasable fastening means such as frangible point bonds may be employed to maintain the absorbent article in a pant configuration until the user intentionally disengages the fasteners.
The fastening system allows for easy inspection of the interior of the pant-like product. If necessary, the fastening system also allows the pant to be removed quickly and easily. This is particularly beneficial when the pant contains messy excrement. If desired, the caregiver can completely remove the pant-like product and replace it with a new one without having to remove the child""s shoes and clothing. The present fastening system may be used with a wide variety of absorbent products, including training pants, diapers, incontinence garments, or other garments using mechanical or adhesive fasteners.
The present invention also pertains to a method of making an absorbent article, which is described in greater detail hereinafter. A more detailed description of the construction and design of one form of training pant can be found in U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompel et al., which is incorporated herein by reference. The Van Gompel et al. patent describes various materials of which the training pant can be made, and a method of constructing a training pant.
Within the context of this specification, each term or phrase below will include the following meaning or meanings.
xe2x80x9cBondedxe2x80x9d refers to the joining, adhering, connecting, attaching, or the like, of two elements. Two elements will be considered to be bonded together when they are bonded directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements.
xe2x80x9cComprisingxe2x80x9d is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.
xe2x80x9cConnectedxe2x80x9d refers to the joining, adhering, bonding, attaching, or the like, of two elements. Two elements will be considered to be connected together when they are connected directly to one another or indirectly to one another, such as when each is directly connected to intermediate elements.
xe2x80x9cDisposablexe2x80x9d refers to articles which are designed to be discarded after a limited use rather than being laundered or otherwise restored for reuse.
xe2x80x9cDisposed,xe2x80x9d xe2x80x9cdisposed onxe2x80x9d and variations thereof are intended to mean that one element can be integral with another element, or that one element can be a separate structure bonded to or placed with or placed near another element.
xe2x80x9cElasticxe2x80x9d and xe2x80x9celasticizedxe2x80x9d mean that property of a material or composite by virtue of which it tends to recover its original size and shape after removal of a force causing a deformation.
xe2x80x9cElastomericxe2x80x9d refers to a material or composite which can be elongated by at least 25 percent of its relaxed length and which will recover, upon release of the applied force, at least 10 percent of its elongation. It is generally preferred that the elastomeric materials or composites be capable of being elongated by at least 100 percent, more preferably by at least 300 percent, of its relaxed length and recover, upon release of an applied force, at least 50 percent of its elongation.
xe2x80x9cFabricsxe2x80x9d is used to refer to all of the woven, knitted and nonwoven fibrous webs.
xe2x80x9cFlexiblexe2x80x9d refers to materials which are compliant and which will readily conform to the general shape and contours of the wearer""s body.
xe2x80x9cForcexe2x80x9d includes a physical influence exerted by one body on another which produces acceleration of bodies that are free to move and deformation of bodies that are not free to move. Force is expressed in grams per unit area.
xe2x80x9cGraphicxe2x80x9d refers to any design, pattern, or the like that is visible on an absorbent article.
xe2x80x9cHydrophilicxe2x80x9d describes fibers or the surfaces of fibers which are wetted by the aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and materials involved. Equipment and techniques suitable for measuring the wettability of particular fiber materials or blends of fiber materials can be provided by a Cahn SFA-222 Surface Force Analyzer System, or a substantially equivalent system. When measured with this system, fibers having contact angles less than 90xc2x0 are designated xe2x80x9cwettablexe2x80x9d or hydrophilic, while fibers having contact angles greater than 90xc2x0 are designated xe2x80x9cnonwettablexe2x80x9d or hydrophobic.
xe2x80x9cIntegralxe2x80x9d is used to refer to various portions of a single unitary element rather than separate structures bonded to or placed with or placed near one another.
xe2x80x9cInwardxe2x80x9d and xe2x80x9coutwardxe2x80x9d refer to positions relative to the center of an absorbent article, and particularly transversely and/or longitudinally closer to or away from the longitudinal and transverse center of the absorbent article.
xe2x80x9cLayerxe2x80x9d when used in the singular can have the dual meaning of a single element or a plurality of elements.
xe2x80x9cLiquid impermeablexe2x80x9d, when used in describing a layer or multi-layer laminate, means that a liquid, such as urine, will not pass through the layer or laminate, under ordinary use conditions, in a direction generally perpendicular to the plane of the layer or laminate at the point of liquid contact. Liquid, or urine, may spread or be transported parallel to the plane of the liquid impermeable layer or laminate, but this is not considered to be within the meaning of xe2x80x9cliquid impermeablexe2x80x9d when used herein.
xe2x80x9cLongitudinalxe2x80x9d and xe2x80x9ctransversexe2x80x9d have their customary meaning, as indicated by the longitudinal and transverse axes depicted in FIGS. 2 and 3. The longitudinal axis lies in the plane of the article and is generally parallel to a vertical plane that bisects a standing wearer into left and right body halves when the article is worn. The transverse axis lies in the plane of the article generally perpendicular to the longitudinal axis. The article as illustrated is longer in the longitudinal direction than in the transverse direction.
xe2x80x9cMemberxe2x80x9d when used in the singular can have the dual meaning of a single element or a plurality of elements.
xe2x80x9cNonwoven webxe2x80x9d means a web of material which is formed without the aid of a textile weaving or knitting process.
xe2x80x9cOperatively joined,xe2x80x9d with reference to the attachment of an elastic member to another element, means that the elastic member when attached to or connected to the element, or treated with heat or chemicals, by stretching, or the like, gives the element elastic properties; and with reference to the attachment of a non-elastic member to another element, means that the member and element can be attached in any suitable manner that permits or allows them to perform the intended or described function of the joinder. The joining, attaching, connecting or the like can be either directly, such as joining either member directly to an element, or can be indirectly by means of another member disposed between the first member and the first element.
xe2x80x9cOuter cover graphicxe2x80x9d refers to a graphic that is directly visible upon inspection of the exterior surface of a garment, and for a refastenable garment is in reference to inspection of the exterior surface of the garment when the fastening system is engaged as it would be during use.
xe2x80x9cPermanently bondedxe2x80x9d refers to the joining, adhering, connecting, attaching, or the like, of two elements of an absorbent garment such that the elements tend to be and remain bonded during normal use conditions of the absorbent garment.
xe2x80x9cRefastenablexe2x80x9d refers to the property of two elements being capable of releasable attachment, separation, and subsequent releasable reattachment without substantial permanent deformation or rupture.
xe2x80x9cReleasably attached,xe2x80x9d xe2x80x9creleasably engagedxe2x80x9d and variations thereof refer to two elements being connected or connectable such that the elements tend to remain connected absent a separation force applied to one or both of the elements, and the elements being capable of separation without substantial permanent deformation or rupture. The required separation force is typically beyond that encountered while wearing the absorbent garment.
xe2x80x9cRupturexe2x80x9d means the breaking or tearing apart of a material; in tensile testing, the term refers to the total separation of a material into two parts either all at once or in stages, or the development of a hole in some materials.
xe2x80x9cStretch bondedxe2x80x9d refers to an elastic member being bonded to another member while the elastic member is extended at least about 25 percent of its relaxed length. Desirably, the term xe2x80x9cstretch bondedxe2x80x9d refers to the situation wherein the elastic member is extended at least about 100 percent, and more desirably at least about 300 percent, of its relaxed length when it is bonded to the other member.
xe2x80x9cStretch bonded laminatexe2x80x9d refers to a composite material having at least two layers in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in an extended condition so that upon relaxing the layers, the gatherable layer is gathered.
xe2x80x9cSurfacexe2x80x9d includes any layer, film, woven, nonwoven, laminate, composite, or the like, whether pervious or impervious to air, gas, and/or liquids.
xe2x80x9cThermoplasticxe2x80x9d describes a material that softens when exposed to heat and which substantially returns to a nonsoftened condition when cooled to room temperature.
These terms may be defined with additional language in the remaining portions of the specification.